Up until recently, I've only had dealings with pretty straightforward
multi-user apps, i.e., small LANs and small numbers of users (5-10).  I now
face a situation where 2 of my clients have merged and want to maintain 2
main offices in different parts of the country.  They are, of course,
concerned about performance (isn't everyone?.  I guess there a number of
ways to do this and many pros and cons.  So, I am now investigating things
such as mirroring the DB at the 2 sites, using some sort of middleware
solution (ASTA, kbmmw, RemObjects, etc), even using Terminal Services for
one of the offices.  I am soliciting suggestions and opinions.

Eric


As a quick, cost effective, relatively easy approach I'd suggest WTS or Citrix as a first look. Its worth looking at the other options for future development but this would allow things to be up and running in a few days (hopefully).

Roy Lambert

Roy,

One of the remote control options will be used short-term, but I'm looking
for some insight into long-term database-specific options since I've never
used any of them before.  Is there a commercial product that will allow
mirroring of dbisam tables?  Will I need to roll my own?  Is middleware a
valid option with a 2 office configuration?  etc.

Eric,

<< Up until recently, I've only had dealings with pretty straightforward
multi-user apps, i.e., small LANs and small numbers of users (5-10).  I now
face a situation where 2 of my clients have merged and want to maintain 2
main offices in different parts of the country.  They are, of course,
concerned about performance (isn't everyone?.  I guess there a number of
ways to do this and many pros and cons.  So, I am now investigating things
such as mirroring the DB at the 2 sites, using some sort of middleware
solution (ASTA, kbmmw, RemObjects, etc), even using Terminal Services for
one of the offices.  I am soliciting suggestions and opinions. >>

I would suggest making one of the offices "remote" until you can get a good
mirroring or shadowing solution in place.  You can do the mirroring or
shadowing using triggers in the DBISAM database server.

--
Tim Young
Elevate Software
www.elevatesoft.com

Eric,

I went down the same route over a year ago and choose kbmMW. You'll
want to check out all middleware and indeed DBISAM's remote systems to
find the one you like but I've never looked back. My client can't
believe the speed and what it brings to them regarding working
remotely and from home.

I move information and documentation between 48 users. Mostly these
are individuals at home, however it also includes two offices with
several users on a LAN. The speed difference (apart from documentation
file sizes) is the same whether you are in the office with the server,
or not - well nearly.

You'd be hard pushed to detect whether the information was on your
machine, or not. In my case it is not.

Go middleware, as you'll never look back. It also teaches you to
better conserve your C/S data movements. Middleware will be the only
solution that will provide workable speed IMO. DBISAM also includes
remote access code, though I've never used this, so you may have all
you need in the box already.

I can recommend kbmMW in a big way, as I'm sure others here can. Done
correctly you can forget any speed issues with regards to the amount
of users and middleware. Forget mirroring data as well (accept for
lookups). Keep it simple and central. There's plenty of people here
and in the respective middleware groups that have made the step you
are looking at, so plenty of resources to assist you.

--
Charles.

> Go middleware, as you'll never look back. It also teaches you to
> better conserve your C/S data movements. Middleware will be the only
> solution that will provide workable speed IMO. DBISAM also includes
> remote access code, though I've never used this, so you may have all
> you need in the box already.

I'd be interested to know what the pros and cons are with Middleware vs
a DBISAM server, if anyone knows.

Regards,

SteveG

Steve,

<< I'd be interested to know what the pros and cons are with Middleware vs a
DBISAM server, if anyone knows. >>

DBISAM is stateful, while most middleware is stateless.  Both have their
advantages/disadvantages depending upon what you want to happen and how busy
the system is.  Stateless architectures are always optimistic in terms of
updates due to the fact that they can be disconnected for long periods of
time before updates are actually submitted.  During that time, the rows that
the updates were executed on may have been changed by someone else, thus
needing reconciliation.  However, most middleware handles this type of thing
rather smoothly.

--
Tim Young
Elevate Software
www.elevatesoft.com

Hi Tim,

> DBISAM is stateful, while most middleware is stateless.  Both have their
> advantages/disadvantages depending upon what you want to happen and how busy
> the system is.  Stateless architectures are always optimistic in terms of
> updates due to the fact that they can be disconnected for long periods of
> time before updates are actually submitted.  During that time, the rows that
> the updates were executed on may have been changed by someone else, thus
> needing reconciliation.  However, most middleware handles this type of thing
> rather smoothly.

Thanks.  I hadn't considered middleware before and was wondering if it
was worth looking into.  I suppose middleware might be useful in very
busy environments with lots of users.  Would it be a good solution where
there are users located in different offices, eg. would there be a speed
advantage?  Is it possible, or perhaps easier, to synchronize two or
more copies of a database with middleware?

Regards,

SteveG

Steve,

<< Thanks.  I hadn't considered middleware before and was wondering if it
was worth looking into.  I suppose middleware might be useful in very busy
environments with lots of users.  Would it be a good solution where there
are users located in different offices, eg. would there be a speed
advantage? >>

It depends upon what the users are trying to accomplish.  If the information
that they are accessing must always be current and up-to-date, then a
straight DBISAM remote connection is the way to go.  If the information can
be slightly stale (such as lookup tables, etc.) then middleware will work
fine.  Even if the lookup tables are stale, however, having RI defined on
the tables at the server side will prevent any rows from being updated using
outdated lookup table rows.

<< Is it possible, or perhaps easier, to synchronize two or more copies of a
database with middleware? >>

It depends upon the middleware.  I believe some support replication, while
others do not.  And, of course, there are products out there that
specifically deal with replication.  Some Google searches should turn up
some good finds.   These are the middleware products that I'm aware of:

ASTA
http://www.astatech.com/index.asp

kbmMW
http://www.components4programmers.com/index.htm

RemObjects
http://www.remobjects.com/

--
Tim Young
Elevate Software
www.elevatesoft.com

Thanks Tim.

Regards,

SteveG